Delayed cerebrovascular reactivity in individuals with spinal cord injury in the right inferior parietal lobe: a breath-hold functional near-infrared spectroscopy study.

Cerebrovascular reactivity (CVR) reflects the ability of blood vessels to dilate or constrict in response to a vasoactive stimulus, and allows researchers to assess the brain's vascular health. Individuals with spinal cord injury (SCI) are at an increased risk for autonomic dysfunction in addition to cognitive impairments, which have been linked to a decline in CVR; however, there is currently a lack of brain-imaging studies that investigate how CVR is altered after SCI. In this study, we used a breath-holding hypercapnic stimulus and functional near-infrared spectroscopy (fNIRS) to investigate CVR alterations in individuals with SCI (n = 20, 14M, 6F, mean age = 46.3 ± 10.2 years) as compared to age- and sex-matched able-bodied (AB) controls (n = 25, 19M, 6F, mean age = 43.2 ± 12.28 years). CVR was evaluated by its amplitude and delay components separately by using principal component analysis and cross-correlation analysis, respectively. We observed significantly delayed CVR in the right inferior parietal lobe in individuals with SCI compared to AB controls (linear mixed-effects model, fixed-effects estimate = 6.565, Satterthwaite's t-test, t = 2.663, p = 0.008), while the amplitude of CVR was not significantly different. The average CVR delay in the SCI group in the right inferior parietal lobe was 14.21 s (sd: 6.60 s), and for the AB group, the average delay in the right inferior parietal lobe was 7.08 s (sd: 7.39 s). CVR delays were also associated with the duration since injury in individuals with SCI, in which a longer duration since injury was associated with a shortened delay in CVR in the right inferior parietal region (Pearson's r-correlation, r = -0.59, p = 0.04). This study shows that fNIRS can be used to quantify changes in CVR in individuals with SCI, and may be further used in rehabilitative settings to monitor the cerebrovascular health of individuals with SCI.

Brain activation during the N-back working memory task in individuals with spinal cord injury: a functional near-infrared spectroscopy study.

Cognitive impairments have frequently been reported in individuals with spinal cord injury (SCI) across different domains such as working memory, attention, and executive function. The mechanism of cognitive impairment after SCI is not well understood due to the heterogeneity of SCI sample populations, and may possibly be due to factors such as cardiovascular dysfunction, concomitant traumatic brain injury (TBI), hypoxia, sleep disorders, and body temperature dysregulation. In this study, we implement the Neuropsychiatric Unit Cognitive Assessment Tool (NUCOG) to assess cognitive differences between individuals with SCI and age-matched able-bodied (AB) controls. We then use an N-back working memory task and functional near-infrared spectroscopy (fNIRS) to elucidate the neurovascular correlates of cognitive function in individuals with SCI. We observed significant differences between the SCI and AB groups on measures of executive function on the NUCOG test. On the N-back task, across the three levels of difficulty: 0-back, 2-back, and 3-back, no significant differences were observed between the SCI and AB group; however, both groups performed worse as the level of difficulty increased. Although there were no significant differences in N-back performance scores between the two groups, functional brain hemodynamic activity differences were observed between the SCI and AB groups, with the SCI group exhibiting higher maximum oxygenated hemoglobin concentration in the right inferior parietal lobe. These findings support the use of fNIRS to study cognitive function in individuals with SCI and may provide a useful tool during rehabilitation to obtain quantitative functional brain activity metrics.

Examination of the Multilevel Sexual Stigma Model of Intimate Partner Violence Risk Among LGBQ+ College Students: A Prospective Analysis Across Eighteen Institutions of Higher Education.

Sexual stigma operates at multiple levels (institutional, group, individual), which serves to disadvantage sexual minority (LGBQ+) individuals and increases risk for deleterious outcomes. The current study evaluated a novel multilevel sexual stigma model of intimate partner violence (MLSSM-IPV) that incorporates multiple levels of sexual stigma as related to IPV risk via several pathways (e.g. hazardous drinking, affective symptoms). We evaluated this model in a longitudinal study of LGBQ+ undergraduate college students (n = 2,415) attending 18 universities who completed surveys in the Fall and Spring semesters. Group-level sexual stigma on each campus was assessed via surveys with heterosexual students (n = 8,517) and faculty, staff, and administrators (n = 2,865), and institutional-level stigma was evaluated via a campus climate assessment. At the campus level, institutional stigma was related to LGBQ+ students' self-stigma and identity concealment. Moreover, self-stigma prospectively predicted IPV victimization, and hazardous drinking mediated the relations between self-stigma and IPV perpetration and victimization. Results suggest that interventions addressing stigma and hazardous drinking may be efficacious in reducing IPV among LGBQ+ students. Further, comprehensive efforts to improve campus climate for LGBQ+ students are likely to produce a plethora of benefits for these students.

Embodying performance excellence in medicine: Can The Six Viewpoints help?

Performance excellence in healthcare relies on skilled situational awareness, but there is no comprehensive framework articulating what within a situation requires awareness. Envisioning medicine as a performing artform, we introduce Mary Overlie's The Six Viewpoints-a comprehensive, yet flexible, conceptual framework used in the performing arts world, for teaching, learning, and creating, for over 50 years. We imagine The Viewpoints could serve as a framework to help improve verbal and non-verbal communication and collaboration on medical teams and between providers and their patients. We call on health professions educators to experiment with The Viewpoints to determine how they could be adapted to support performance excellence in the medical arena.

The significance and limited influence of cerebrovascular reactivity on age and sex effects in task- and resting-state brain activity.

Functional MRI measures the blood-oxygen-level dependent signals, which provide an indirect measure of neural activity mediated by neurovascular responses. Cerebrovascular reactivity affects both task-induced and resting-state blood-oxygen-level dependent activity and may confound inter-individual effects, such as those related to aging and biological sex. We examined a large dataset containing breath-holding, checkerboard, and resting-state tasks. We used the breath-holding task to measure cerebrovascular reactivity, used the checkerboard task to obtain task-based activations, and quantified resting-state activity with amplitude of low-frequency fluctuations and regional homogeneity. We hypothesized that cerebrovascular reactivity would be correlated with blood-oxygen-level dependent measures and that accounting for these correlations would result in better estimates of age and sex effects. We found that cerebrovascular reactivity was correlated with checkerboard task activations in the visual cortex and with amplitude of low-frequency fluctuations and regional homogeneity in widespread fronto-parietal regions, as well as regions with large vessels. We also found significant age and sex effects in cerebrovascular reactivity, some of which overlapped with those observed in amplitude of low-frequency fluctuations and regional homogeneity. However, correcting for the effects of cerebrovascular reactivity had very limited influence on the estimates of age and sex. Our results highlight the limitations of accounting for cerebrovascular reactivity with the current breath-holding task.

Cerebrovascular reactivity increases across development in multiple networks as revealed by a breath-holding task: A longitudinal fMRI study.

Functional magnetic resonance imaging (fMRI) has been widely used to understand the neurodevelopmental changes that occur in cognition and behavior across childhood. The blood-oxygen-level-dependent (BOLD) signal obtained from fMRI is understood to be comprised of both neuronal and vascular information. However, it is unclear whether the vascular response is altered across age in studies investigating development in children. Since the breath-hold (BH) task is commonly used to understand cerebrovascular reactivity (CVR) in fMRI studies, it can be used to account for developmental differences in vascular response. This study examines how the cerebrovascular response changes over age in a longitudinal children's BH data set from the Nathan Kline Institute (NKI) Rockland Sample (aged 6-18 years old at enrollment). A general linear model approach was applied to derive CVR from BH data. To model both the longitudinal and cross-sectional effects of age on BH response, we used mixed-effects modeling with the following terms: linear, quadratic, logarithmic, and quadratic-logarithmic, to find the best-fitting model. We observed increased BH BOLD signals in multiple networks across age, in which linear and logarithmic mixed-effects models provided the best fit with the lowest Akaike information criterion scores. This shows that the cerebrovascular response increases across development in a brain network-specific manner. Therefore, fMRI studies investigating the developmental period should account for cerebrovascular changes that occur with age.

Factors that determine first intubation attempt success in high-risk neonates.

BACKGROUND: Approximately 50% of all neonatal endotracheal intubation attempts are unsuccessful and associated with airway injury and cardiorespiratory instability. The aim of this study was to describe intubation practice at a high-risk Neonatal Intensive Care Unit (NICU) and identify factors associated with successful intubation at the first attempt. METHODS: Retrospective cohort study of all infants requiring intubation within the Royal Children's Hospital NICU over three years. Data was collected from the National Emergency Airway Registry for Neonates (NEAR4NEOS). Outcomes were number of attempts, level of operator training, equipment used, difficult airway grade, and clinical factors. Univariate and multivariate analysis were performed to determine factors independently associated with first attempt success. RESULTS: Three hundred and sixty intubation courses, with 538 attempts, were identified. Two hundred and twenty-five (62.5%) were successful on first attempt, with similar rates at subsequent attempts. On multivariate analysis, increasing operator seniority increased the chance of first attempt success. Higher glottic airway grades were associated with lower chance of first attempt success, but neither a known difficult airway nor use of a stylet were associated with first attempt success. CONCLUSION: In a NICU with a high rate of difficult airways, operator experience rather than equipment was the greatest determinant of intubation success. IMPACT: Neonatal intubation is a high-risk lifesaving procedure, and this is the first report of intubation practices at a quaternary surgical NICU that provides regional referral services for complex medical and surgical admissions. Our results showed that increasing operator seniority and lower glottic airway grades were associated with increased first attempt intubation success rates, while factors such as gestational age, weight, stylet use, and known history of difficult airway were not. Operator factors rather than equipment factors were the greatest determinants of first attempt success, highlighting the importance of team selection for neonatal intubations in a high-risk cohort of infants.

Multifractal long-range dependence pattern of functional magnetic resonance imaging in the human brain at rest.

Long-range dependence is a prevalent phenomenon in various biological systems that characterizes the long-memory effect of temporal fluctuations. While recent research suggests that functional magnetic resonance imaging signal has fractal property, it remains unknown about the multifractal long-range dependence pattern of resting-state functional magnetic resonance imaging signals. The current study adopted the multifractal detrended fluctuation analysis on highly sampled resting-state functional magnetic resonance imaging scans to investigate long-range dependence profile associated with the whole-brain voxels as specific functional networks. Our findings revealed the long-range dependence's multifractal properties. Moreover, long-term persistent fluctuations are found for all stations with stronger persistency in whole-brain regions. Subsets with large fluctuations contribute more to the multifractal spectrum in the whole brain. Additionally, we found that the preprocessing with band-pass filtering provided significantly higher reliability for estimating long-range dependence. Our validation analysis confirmed that the optimal pipeline of long-range dependence analysis should include band-pass filtering and removal of daily temporal dependence. Furthermore, multifractal long-range dependence characteristics in healthy control and schizophrenia are different significantly. This work has provided an analytical pipeline for the multifractal long-range dependence in the resting-state functional magnetic resonance imaging signal. The findings suggest differential long-memory effects in the intrinsic functional networks, which may offer a neural marker finding for understanding brain function and pathology.

The Significance and Limited Influence of Cerebrovascular Reactivity on Age and Sex Effects in Task- and Resting-State Brain Activity.

Functional MRI (fMRI) measures the blood-oxygen-level dependent (BOLD) signals, which provide an indirect measure of neural activity mediated by neurovascular responses. Cerebrovascular reactivity affects both task-induced and resting-state BOLD activity and may confound inter-individual effects observed in BOLD-based measures, such as those related to aging and biological sex. To investigate this, we examined a large open-access fMRI dataset containing a breath-holding task, checkerboard task, and resting-state scans. We used the breath-holding task to measure cerebrovascular reactivity, used the checkerboard task to obtain task-based activations, and from the resting-state data, we quantified the resting-state amplitude of low-frequency fluctuations (ALFF), and resting-state regional homogeneity (ReHo). We hypothesized that cerebrovascular reactivity would be correlated with BOLD measures and that accounting for these correlations would result in better estimates of age and sex effects. Our analysis showed that cerebrovascular reactivity was correlated with checkerboard task activations in the visual cortex and with ALFF and ReHo in widespread fronto-parietal regions, as well as regions with large vessels. We also found significant age and sex effects in cerebrovascular reactivity, some of which overlapped with those observed in ALFF and ReHo scores. Finally, we demonstrated that correcting for the effects of cerebrovascular reactivity had very limited influence on the estimates of age and sex. Our results highlight the limitations of accounting for cerebrovascular reactivity with the current breath-holding task.

A Latent Transition Model of the Effects of a Youth-Led Sexual Violence Prevention Initiative on Victimization and Perpetration Trajectories Over Time.

PURPOSE: Latent transition analysis was used to characterize transitions over time in profiles of victimization and perpetration of sexual and related forms of violence (i.e., bullying, dating violence, sexual harassment) over a 2.5-year period among middle and high school students. We also examined how profiles of violence varied as a function of participation in a youth-led sexual violence prevention initiative (Youth Voices in Prevention [Youth VIP]). METHODS: Participants were 2,528 youth (53.3% female, average age = 13.73 years) who completed a survey at five points (every six months) over three academic years (fall 2017-fall 2019). Participation in Youth VIP was tracked by researchers and took place from summer 2018 to fall 2019. RESULTS: Four classes (i.e., low violence class, victimization only class, sexual harassment class, mixed violence class) best captured patterns of victimization and perpetration experiences. The latent transition analysis showed that the least severe class had the highest stability, with the fewest students transitioning out of this class over time. Results also demonstrated that, overall, participation in at least one Youth VIP event, compared to not participating in any Youth VIP events, related to positive transitions over time to less severe classes. DISCUSSION: Violence experienced by youth is not homogenous, although classes of violence among youth are generally stable over a 2.5 period. Results also provide further evidence that Youth VIP is a promising approach to prevent sexual and related forms of violence and appears to promote transition into less severe classes of violence over time.

Cerebrovascular reactivity increases across development in multiple networks as revealed by a breath-holding task: a longitudinal fMRI study.

Functional magnetic resonance imaging (fMRI) has been widely used to understand the neurodevelopmental changes that occur in cognition and behavior across childhood. The blood-oxygen-level-dependent (BOLD) signal obtained from fMRI is understood to be comprised of both neuronal and vascular information. However, it is unclear whether the vascular response is altered across age in studies investigating development in children. Since the breath-hold task is commonly used to understand cerebrovascular reactivity in fMRI studies, it can be used to account for developmental differences in vascular response. This study examines how the cerebrovascular response changes over age in a longitudinal children's breath-hold dataset from the Nathan Kline Institute (NKI) Rockland Sample (ages 6 to 18 years old at enrollment). A general linear model (GLM) approach was applied to derive cerebrovascular reactivity from breath-hold data. To model both the longitudinal and cross-sectional effects of age on breath-hold response, we used mixed effects modeling with the following terms: linear, quadratic, logarithmic, and quadratic-logarithmic, to find the best-fitting model. We observed increased breath-hold BOLD signal in multiple networks across age, in which linear and logarithmic mixed effects models provided the best fit with the lowest Akaike Information Criterion (AIC) scores. This shows that the cerebrovascular response increases across development in a brain network-specific manner. Therefore, fMRI studies investigating the developmental period should account for cerebrovascular changes which occur with age.

Task-Based and Resting-State Cortical Functional Differences After Spinal Cord Injury: A Pilot Functional Near-Infrared Spectroscopy Study.

Brain reorganization following spinal cord injury (SCI) has been well-established using animal and human studies. Yet, much is unknown regarding functional recovery and adverse secondary outcomes after SCI. Functional near-infrared spectroscopy (fNIRS) is a neuroimaging technique that offers methodological flexibility in a real-world setting. We used fNIRS to examine the cortical functional differences between 12 males with thoracolumbar SCI (46.41 ± 11.09 years of age) and 12 healthy males (47.61 ± 11.94 years of age) during resting state and task conditions-bilateral finger tapping (FT), mental imagery of bilateral FT with action observation (FTI+AO), and bilateral ankle tapping (AT). We found an overall decrease in hemodynamic response of the SCI group during all three task conditions. Task modulated functional connectivity (FC) computed using beta series correlation technique was compared using independent sample t-tests at α = 0.05. Connectivity between the right mediolateral sensorimotor network (SMN) and the right medial SMN was reduced during the FT task in SCI. A mixed analysis of variance revealed that the FC within the right mediolateral SMN was reduced during FT but preserved during FTI+AO (i.e., comparable to controls) in the SCI group. Lower FC of these regions was associated with longer injury durations. Additionally, we found a general decrease in resting state FC of the SCI group, specifically in the Slow-3 frequency range (0.073 to 0.1 Hz). These results, though preliminary, are consistent with past studies and highlight the potential of fNIRS in SCI and rehabilitative research.

Analysis and visualization methods for detecting functional activation using laser speckle contrast imaging.

BACKGROUND: Previous studies have used regional cerebral blood flow (CBF) hemodynamic response to measure brain activities. In this work, we use a laser speckle contrast imaging (LSCI) apparatus to sample the CBF activation in somatosensory cortex (S1BF) with repetitive whisker stimulation. Traditionally, the CBF activations were processed by depicting the change percentage above baseline; however, it is not clear how different methods influence the detection of activations. AIMS: Thus, in this work we investigate the influence of different methods to detect activations in LSCI. MATERIALS & METHODS: First, principal component analysis (PCA) was performed to denoise the CBF signal. As the signal of the first principal component (PC1) showed the highest correlation with the S1BF CBF response curve, PC1 was used in the subsequent analyses. Then, we used fast Fourier transform (FFT) to evaluate the frequency properties of the LSCI images and the activation map was generated based on the amplitude of the central frequency. Furthermore, Pearson's correlation coefficient (C-C) analysis and a general linear model (GLM) were performed to estimate the S1BF activation based on the time series of PC1. RESULTS: We found that GLM performed better in identifying activation than C-C. Additionally, the activation maps generated by FFT were similar to those obtained by GLM. Particularly, the superficial vein and arterial vessels separated the activation region as segmented activated areas, and the regions with unresolved vessels showed a common activation for whisker stimulation. DISCUSSION AND CONCLUSION: Our research analyzed the extent to which PCA can extract meaningful information from the signal and we compared the performance for detecting brain functional activation between different methods that rely on LSCI. This can be used as a reference for LSCI researchers on choosing the best method to estimate brain activation.

Global Network Analysis of Alzheimer's Disease with Minimum Spanning Trees.

BACKGROUND: A minimum spanning tree (MST) is a unique efficient network comprising the necessary connections needed to connect all regions in a network while retaining the lowest possible cost of connection weight. OBJECTIVE: This study aimed to utilize functional near-infrared spectroscopy (fNIRS) to analyze brain activity in different regions and then construct MST-based regions to characterize the brain topologies of participants with Alzheimer's disease (AD), mild cognitive impairment (MCI), and normal controls (NC). METHODS: A 46 channel fNIRS setup was used on all participants, with correlation being calculated for each channel pair. An MST was constructed from the resulting correlation matrix, from which graph theory measures were calculated. The average number of connections within a lobe in the left versus right hemisphere was calculated to identify which lobes displayed and abnormal amount of connectivity. RESULTS: Compared to those in the MCI group, the AD group showed a less integrated network structure, with a higher characteristic path length, but lower leaf fraction, maximum degree, and degree divergence. The AD group also showed a higher number of connections in the frontal lobe within the left hemisphere and a lower number between hemispheric frontal lobes as compared to MCI. CONCLUSION: These results indicate a deviation in network structure and connectivity within patient groups that is consistent with the theory of dysconnectivity for AD. Additionally, the AD group showed strong correlations between the Hamilton depression rating scale and different graph metrics, suggesting a link between network organization and the recurrence of depression in AD.

Examining long-term intervention effects to promote teacher problem-solving and communication skills in the rural context.

Conjoint behavioral consultation (CBC), a teacher-parent partnership intervention, has been shown to yield immediate improvements in problem-solving skills and communication quality with parents for kindergarten through third grade teachers in rural schools. The purpose of the present study was to determine whether CBC can yield maintained effects on teacher skills and communication over a 1-year follow-up period. We used an experimental design to examine maintenance effects of CBC (nCBC = 84, nControl = 68). Outcomes were assessed four times: baseline, 12-week posttest (immediate effects), and twice during a 1-year follow-up period (maintenance effects). Longitudinal growth modeling revealed that immediate improvements in perceived problem-solving competence and communication quality with parents for teachers in the CBC condition compared to teachers in the control condition were maintained 1-year postintervention. CBC appears to support teachers' professional practices over time. Implications for enhancing families' and schools' capacities to address student behavior concerns are discussed. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Cognitive control inhibition networks in adulthood are impaired by early iron deficiency in infancy.

Iron deficiency, a common form of micronutrient deficiency, primarily affects children and women. The principal cause of iron deficiency is undernutrition in low-income countries and malnutrition in middle to upper income regions. Iron is a key element for myelin production, neuronal metabolism, and dopamine functions. Iron deficiency in early life can alter brain development and exert long-lasting effects. Control inhibition is an executive function that involves several brain regions, including the prefrontal cortex and caudate and sub-thalamic nuclei. Dopamine is the prevalent neurotransmitter underlying cognitive inhibition. We followed cohort study participants who had iron deficiency anemia in infancy as well non-anemic controls. At 22 years of age, the participants were subjected to functional magnetic resonance imaging (fMRI) to evaluate the correlation between functional connectivity and performance on an inhibitory cognitive task (Go/No-Go). We hypothesized that former iron deficient anemic (FIDA) participants demonstrate less strength in functional connectivity compared with controls (C). There were not significant group differences in the behavioral results in terms of accuracy and response time. A continuous covariate interaction analysis of functional connectivity and the Go/No-Go scores demonstrated significant differences between the FIDA and C groups. The FIDA participants demonstrated less strength in connectivity in brain regions related to control inhibition, including the medial temporal lobe, impairment in the integration of the default mode network (indicating decreased attention and alertness), and an increase in connectivity in posterior brain areas, all of which suggest slower circuitry maturation. The results support the hypothesis that FIDA young adults show differences in the connectivity of networks related to executive functions. These differences could increase their vulnerability to develop cognitive dysfunctions or mental disorders in adulthood.

A Metal-Organic Framework (MOF)-Based Multifunctional Cargo Vehicle for Reactive-Gas Delivery and Catalysis.

The efficient delivery of reactive and toxic gaseous reagents to organic reactions was studied using metal-organic frameworks (MOFs). The simultaneous cargo vehicle and catalytic capabilities of several MOFs were probed for the first time using the examples of aromatization, aminocarbonylation, and carbonylative Suzuki-Miyaura coupling reactions. These reactions highlight that MOFs can serve a dual role as a gas cargo vehicle and a catalyst, leading to product formation with yields similar to reactions employing pure gases. Furthermore, the MOFs can be recycled without sacrificing product yield, while simultaneously maintaining crystallinity. The reported findings were supported crystallographically and spectroscopically (e.g., diffuse reflectance infrared Fourier transform spectroscopy), foreshadowing a pathway for the development of multifunctional MOF-based reagent-catalyst cargo vessels for reactive gas reagents as an attractive alternative to the use of toxic pure gases or gas generators.

Who will receive the last ventilator: why COVID-19 policies should not prioritise healthcare workers.

Policies promoted and adopted for allocating ventilators during the COVID-19 pandemic have often prioritised healthcare workers or other essential workers. While the need for such policies has so far been largely averted, renewed stress on health systems from continuing surges, as well as the experience of allocating another scarce resource-vaccination-counsel revisiting the justifications for such prioritisation. Prioritising healthcare workers may have intuitive appeal, but the ethical justifications for doing so and the potential harms that could follow require careful analysis. Ethical justifications commonly offered for healthcare worker prioritisation for ventilators rest on two social value criteria: (1) instrumental value, also known as the 'multiplier effect', which may preserve the ability of healthcare workers to help others, and (2) reciprocity, which rewards past usefulness or sacrifice. We argue that these justifications are insufficient to over-ride the common moral commitment to value each person's life equally. Institutional policies prioritising healthcare workers over other patients also violate other ethical norms of the healthcare professions, including the commitment to put patients first. Furthermore, policy decisions to prioritise healthcare workers for ventilators could engender or deepen existing distrust of the clinicians, hospitals and health systems where those policies exist, even if they are never invoked.

Comparing Alternative Corrections for Bias in the Bias-Corrected Bootstrap Test of Mediation.

Although the bias-corrected (BC) bootstrap is an often-recommended method for testing mediation due to its higher statistical power relative to other tests, it has also been found to have elevated Type I error rates with small sample sizes. Under limitations for participant recruitment, obtaining a larger sample size is not always feasible. Thus, this study examines whether using alternative corrections for bias in the BC bootstrap test of mediation for small sample sizes can achieve equal levels of statistical power without the associated increase in Type I error. A simulation study was conducted to compare Efron and Tibshirani's original correction for bias, z0, to six alternative corrections for bias: (a) mean, (b-e) Winsorized mean with 10%, 20%, 30%, and 40% trimming in each tail, and (f) medcouple (robust skewness measure). Most variation in Type I error (given a medium effect size of one regression slope and zero for the other slope) and power (small effect size in both regression slopes) was found with small sample sizes. Recommendations for applied researchers are made based on the results. An empirical example using data from the ATLAS drug prevention intervention study is presented to illustrate these results. Limitations and future directions are discussed.